In this work, I propose to characterize two isoforms of the nuclear receptor corepressor SMRT with respect to their ability to interact with various nuclear hormone receptors and their ability to effect transcriptional repression. I will also analyze the expression of these isoforms in different tissue to determine if expression of these isoforms are regulated and to potentially gain insight into the physiological roles these isoforms may play. In addition, I will develop an algorithm, which will use data from the EST database to identify other splicing isoforms of SMRT.